While analysts warn that their understanding of the invasion is incomplete, the evidence for shortcomings in Russian logistics is evident in verified social-media footage of stalled Russian convoys and broken-down tanks, some confirmed by commercial satellite photographs. Russian forces have struggled with the transport of fuel and ammunition as well as food and clothing for soldiers at the front…

Mr. Barry said more than 170,000 Russian troops are estimated to have been committed to Ukraine in about 130 units, known as battalion tactical groups. When the U.S. and its allies invaded Iraq in 2003, similar numbers of U.S. troops were committed in fewer than 50 BTGs. The reason for the difference: the large proportion of the U.S. force being used for logistics and the transportation of fuel, ammunition, water and food.

Phillips O’Brien, professor of strategic studies at the University of St. Andrews in Scotland, said military experts may have been deceived by the “lavish logistical system” employed by the U.S. in the past three decades. “What the U.S. has done has made people immune to looking at the reality of logistics and just assuming it will get done,” he said.

He said the complexity of the Russian operation compounded problems of logistics. “What they were actually trying to do was logistically bonkers. They were trying to support five or six different axes of advance in a hugely spread-out arch, all the way from west of Kyiv, all of that bulge of eastern Ukraine, down to Crimea.”